Objective: To investigate the clinical characteristics, etiology, treatment outcomes, and prognostic factors of sudden sensorineural hearing loss (SSNHL) in children to guide the clinical diagnosis and treatment of SSNHL in the pediatric population. Study Design: Retrospective case review. Setting: Tertiary referral center. Patients: Patients diagnosed with SSNHL from November 2011 to December 2017 with relatively complete clinical data. Intervention: Diagnosis and systemic treatment of SSNHL. Main Outcome Measures: Patients' clinical characteristics, etiology, laboratory tests, imaging, pure-tone audiometry at admission, and discharge were analyzed. Results: A total of 25 children and 149 adults with SSNHL were included. Recent or previous viral infection rates (81.8%) and fasting blood glucose level (5.23+1.47 mmol/L) in children with SSNHL were lower than those in adult SSNHL patients (p = 0.033, p = 0.033). Autoimmune abnormalities (90.0%) and plasma fibrinogen abnormalities (27.3%) were higher in children with SSNHL than those in adult SSNHL patients (40.0%, 8.8%, respectively, p < 0.05). The recovery rate in children (38.4%) with SSNHL is comparable to that in adults (22.6%), but children have a higher complete rate compared to adults (26.9%, 11.3%, respectively, p < 0.05). Children with a profound audiometric curve had a worse prognosis in comparison to other types of audiometric curves (p = 0.041). Conclusions: Children with SSNHL have a lower rate of viral infection in comparison to adults with SSNHL. Fasting blood glucose levels, complement C3, C4, and fibrinogen may be closely related to childhood SSNHL. The recovery rate in children with SSNHL is comparable to that in adults, but children have a higher complete rate compared to adults. A profound hearing curve is an unfavorable prognostic factor in both children and adults with SSNHL.